<!DOCTYPE html>
<html>
<!-- Created by GNU Texinfo 7.1, https://www.gnu.org/software/texinfo/ -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<!-- This file documents the use of the GNU compilers.

Copyright © 1988-2023 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with the
Invariant Sections being "Funding Free Software", the Front-Cover
Texts being (a) (see below), and with the Back-Cover Texts being (b)
(see below).  A copy of the license is included in the section entitled
"GNU Free Documentation License".

(a) The FSF's Front-Cover Text is:

A GNU Manual

(b) The FSF's Back-Cover Text is:

You have freedom to copy and modify this GNU Manual, like GNU
     software.  Copies published by the Free Software Foundation raise
     funds for GNU development. -->
<title>Using fast enumeration (Using the GNU Compiler Collection (GCC))</title>

<meta name="description" content="Using fast enumeration (Using the GNU Compiler Collection (GCC))">
<meta name="keywords" content="Using fast enumeration (Using the GNU Compiler Collection (GCC))">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta name="viewport" content="width=device-width,initial-scale=1">

<link href="index.html" rel="start" title="Top">
<link href="Indices.html" rel="index" title="Indices">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Fast-enumeration.html" rel="up" title="Fast enumeration">
<link href="c99_002dlike-fast-enumeration-syntax.html" rel="next" title="c99-like fast enumeration syntax">
<style type="text/css">
<!--
a.copiable-link {visibility: hidden; text-decoration: none; line-height: 0em}
div.example {margin-left: 3.2em}
kbd.key {font-style: normal}
span:hover a.copiable-link {visibility: visible}
-->
</style>


</head>

<body lang="en_US">
<div class="subsection-level-extent" id="Using-fast-enumeration">
<div class="nav-panel">
<p>
Next: <a href="c99_002dlike-fast-enumeration-syntax.html" accesskey="n" rel="next">C99-Like Fast Enumeration Syntax</a>, Up: <a href="Fast-enumeration.html" accesskey="u" rel="up">Fast Enumeration</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Indices.html" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<h4 class="subsection" id="Using-Fast-Enumeration"><span>8.9.1 Using Fast Enumeration<a class="copiable-link" href="#Using-Fast-Enumeration"> &para;</a></span></h4>

<p>GNU Objective-C provides support for the fast enumeration syntax:
</p>
<div class="example smallexample">
<pre class="example-preformatted">  id array = ...;
  id object;

  for (object in array)
  {
    /* Do something with 'object' */
  }
</pre></div>

<p><code class="code">array</code> needs to be an Objective-C object (usually a collection
object, for example an array, a dictionary or a set) which implements
the &ldquo;Fast Enumeration Protocol&rdquo; (see below).  If you are using a
Foundation library such as GNUstep Base or Apple Cocoa Foundation, all
collection objects in the library implement this protocol and can be
used in this way.
</p>
<p>The code above would iterate over all objects in <code class="code">array</code>.  For
each of them, it assigns it to <code class="code">object</code>, then executes the
<code class="code">Do something with 'object'</code> statements.
</p>
<p>Here is a fully worked-out example using a Foundation library (which
provides the implementation of <code class="code">NSArray</code>, <code class="code">NSString</code> and
<code class="code">NSLog</code>):
</p>
<div class="example smallexample">
<pre class="example-preformatted">  NSArray *array = [NSArray arrayWithObjects: @&quot;1&quot;, @&quot;2&quot;, @&quot;3&quot;, nil];
  NSString *object;

  for (object in array)
    NSLog (@&quot;Iterating over %@&quot;, object);
</pre></div>


</div>



</body>
</html>
